Cooling system



Dec. 22, 1942.

O. OECKL COOLING SYSTEM Filed June .13. 1959 2 Sheets-Sheet 1 w r n 0 iZ. w

m 4 ......0 u .2 m w no I .7, 1 a Q a Dec. 22, 1942. o. OECKL COOLINGSYSTEM Filed June 13, 1939 2 Sheets-Sheet 2 Inventor" atented 6632, 19422,305,811 coomNG SYSTEM Otto Oeckl, Berlin- Schoneberg, Germany; vestedin the Alien Property Custodian Application June 13, 1939, Serial No.278,951 In Germany June 17, 1938 3 Claims.

This invention relates to apparatus for the heat treatment or thermalrefinement of light metal work pieces. The mechanical strength ofvarious light metal alloys, such as that known as Duralumin can beenhanced by-a special heat treating or tempering process which must beap-' plied to the work piece after the same has obtained its finalshape. The said thermal refinement consists of a heat treatment and asubsequent rapid cooling or quenching. The tempera- .vide means forcarrying out the cooling opera tion in a. manner to ensure optimumconditions with respect to the structure, shape and dimen clons of thework piece.

A special object of the invention is to avoid the use of a cooling bathwhich would cause corrocion of the work piece and to cool the work piecevery uniformly so as to avoid detrimental me chanical stresses anddeformation of the work piece.

With these and further objects in view, as may become apparent from thewithin disclosures, the invention consists not only in the structuresherein pointed out and illustrated by the drawlugs, but includes furtherstructures coming within the scope of what hereinafter may he claimed.

The character of the invention, however, may be bestunderstood byreference to certain of its structural forms, as illustrated by theaccompanying drawings in which- Fig. l is a perspective, sectional viewofa cooling chamber adapted for carrying out the invention.

Fig. 2 is a cross section of the cooling chamber shown in Fig. 1..

Fig. 3 is an axial section of a nozzle for use in said cooling chamber.

Fig. it is a similar cross section as ing the cooling chamber equippedfor of small work-pieces.

Fig. 5 is a working diagram of a cooling systern having the inventionapplied thereto.

Fig. 2, showthe cooling (Cl. 266 m Similar reference numerals denotesimilar parts in the different views.

As here shown, I enclose the annealed articles in a quenching chamberwhich is filled with a gaseous fluid and I produce around the article asubstantially homogeneous and slowly moving cloud of a quenching fluidby exhausting the gaseous fluid from the chamber and feedingsimultaneously fresh quenching fluid to said cloud in such a manner thatsaid fresh quenching fluid is prevented from directly impinging uponsaid articles in the form of a cold stream. In this manner, the wholework piece or pieces are uniformly and homogeneously cooled anddeformation or warping or structural tensions in the work piece areavoided. It is thus possible to produce very complicated parts bypressing, stretching or bending in a single operation, becausesubsequent working of the work piece is no m re required. I'he workpiece may be of any desired size, and assembled airplane parts, forexample,

- tail plane surfaces, body parts etc. may be made of soft sheet metaland soft rivets and refined in their finished shape.

The cooling fluid may be supplied through nozzles in the walls of thecooling chamber and, additionally, supply means may be providedcentrally in the chamber, for instance, for the cooling of hollow bodiesfrom the interior and exterior side.

According to a special feature of the invention, separate control meansmay be provided for the various nozzles so as to provide a differentsupply of the cooling fluid at the various points of the work piece inaccordance with the different wall thicknesses, shape or other featureswhich may require different cooling action at the respective points.Also, the exhaust can be provided with regulating means.

As here shown, a single cooling chamber may be used for quenching anywork pieces of different size and shape. To this end, a great number ofsupply nozzles are uniformly distributed on the cylindrical walls of thechamber and additional supporting means may be inserted in the chamberfor supporting additional supply nozzles and/or for carrying smallerwork pieces.

Referring now to the drawings in greater de tail, and first to Figs. 1and 2., it will be seen that a substantially cylindrical cooling chamberi is provided with a hinged front cover 2 and a fixed conical and cover3 which terminates in an exhaust pipe a in a bend of which an exhaustor5 is rotatably mounted by a bearing bush 6 through which the exhaust-orshaft l extends.

The shaft 1 is driven from the motor 8, through a bevel gear 8. A workpiece 13 which may be a body of an airplane is placed on a platform carII on rails l and held thereon in position by means of stays I2 and i4and a strip l5. Radiallymounted in the cylindrical shell i of thechamber are feed nozzles l8 communicating with a feed pipe system l1,l8, l9. Further feed nozzles 20 are provided in the floor andcommunicate with the same pipe system. Moreover, a pipe system 2|, 22,23 on the platform car, carrying nozzles 24 in apredetermined-relationship within and around the work piece, can becoupled with said feed pipe system, by a flexible pipe or coupling hose25. Control valves 26, 21, 28, 29, 30 permit individual adjustment ofthe quantity of the cooling fluid or fluids supplied to each nozzle soas to adapt the cooling action of the various nozzles to the specialrequirements of the diiferent portions of the work piece. For example,portions of a greater wall thickness will require a more intensivecooling action than portions of a smaller wall thickness in order toensure a uniform cooling of the whole work piece without structuraltensions,

The nozzles may be of any suitable construction to permit atomising ofthe cooling fluid as it leaves the nozzle and to form a substantiallyhomogeneous cloud of the cooling fluid around the work piece.Advantageously the nozzles are provided to permit the discharge of amixture of two or more different cooling fluids, for instance, air andwater, as will hereafter be described.

A type of nozzle which is suitable for the said purpose is illustratedby way of example in Fig. 3, from which it will be noted that twoseparate passages 3|, 32 which can be controlled separately by controlvalves 33 and 34, serve for the supply of compressed air and water tothe chamber 35 in which the air and water streams are mixed with eachother; the mixture leaving said chamber 35 is atomised to form a cloudof air and water vapour 36, without forming a jet or sharply definedcurrent of cooling fluid in the axial direction of the nozzle or in theradial direction of the chamber which might impinge upon the work piecedirectly and cause excessive cooling of any small regions of the workpiece.

It will be noted from Figs. 1 and 2 that angle rails 31 and 38 aresecured to the sides of the chamber I. Said angle rails may serve tocarry additional platform cars 35 and Gil, as shown in Fig. 4, for thereception of smaller work pieces 4!. Supply pipes 82 for the coolingfluid may be secured to these cars if desired. Additional pipes 42 canbe attached to suction devices in the case of different work pieceshapes; in any case, with such additional pipes, the distribution andthe movement of cooling agent can be affected as desired and adjusted tothe requirements of the work pieces.

Where feed nozzles are used which produce a more or less sharply definedjet or current, the same will be directed tangentially with respect tothe cylindrical chamber, e. g., as indicated at 49 in Fig. 4, so as toavoid any direct contact of the said cold jet with the work piece.

Referring to Fig. 5, it will be seen that the gaseous cooling fluidwhich has been supplied to the cooling chamber i from a compressor 43,through the nozzles l6, after its discharge through the exhaust pipe isrecooled by passage through a recooling apparatus 54 to which coolingWater may be supplied from a main water pipe 45 through a duct 46, andthen recycled by the compressor 43. A pipe 41 communicating with thesame water pipe 45 may feed fresh cooling water to the nozzle asillustrated. The water may be separated from the air in the recoolingapparatus and drawn of! by a tap 48.

It will thus be seen that the work piece or work pieces are enclosed ina substantially homogeneous and uniform cloud of the cooling fluid whichproceeds slowly to the exhaust, along the walls of the work piece,without causing any excessive coolingaction at the points where thefresh cooling fluid enters through the nozzles, so that the work piecesare cooled rapidly but uniformly, and warping or deformation orstructural tensions of the work pieces are avoided.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention.

I claim:

1. In a cooling system for quenching annealed articles formed of lightmetal, especially annealed articles stamped or drawn from sheets oflight metal, of the type including a closed cooling chamber, means forsupporting the annealed articles at locations adjacent the center ofsaid chamber, and an exhaust port adjacent one end of said chamber, thecombination of a plurality of diffusing nozzles disposed in spacedrelation about the walls of said chamber on opposite sides of thecentral portion of the latter and adapted to discharge into theperipheral zone only of said chamber an aeroform quenching fluid freefrom liquid components, means for supplying a quenche ing fluidcomponent, under pressure, to said nozzles, and means in cooperationwith said exhaust port for slowly moving said quenching atmosphere fromsaid peripheral zone over the supported annealed articles and to saidexhaust port as fresh quenching atmosphere is formed in, the peripheralzone of said chamber, said atmosphere-moving means and said nozzlescooperating to surround the supported annealed articles substantially onall sides with a slowly moving, homogeneous and uniform, quenchingatmosphere consisting of said aeroform quenching fluid.

2. In a cooling system for quenching annealed articles formed of lightmetal, especially annealed articles stamped or drawn from sheets oflight metal, of the type including a closed cooling chamber, means forsupporting the annealed articles at locations adjacent the center ofsaid chamber, and an exhaust port adjacent one end of said chamber, thecombination of a plurality of diifusing nozzles disposed in spacedrelation about the walls of said chamber on opposite sides of thecentral portion of the latter and adapted to discharge into theperipheral zone only of said chamber an aeroform quenching fluid freefrom liquid components, means for supplying a vaporizable liquid andcold gaseous fluid, under pressure, to said nozzles, and means incooperation with said exhaust port for slowly moving said quenchingatmosphere from said peripheral zone over the supported annealedarticles and to said exhaust port as fresh quenching atmosphere isformed in the peripheral zone of said chamber, said atmosphere-movingmeans and said nozzles cooperating to surround the supported annealedarticles substantially on all sides with a slowly moving, homogeneousand uniform, quenching atmosphere consisting of said aeroform quenchingfluid.

3. In a cooling system for quenching annealed articles formed of lightmetal, especially annealed articles stamped or drawn from sheets oflight metal, of the type including a closed cooling chamber, means forsupporting the annealed articles at locations adjacent the center ofsaid chamber, and an exhaust port adjacent one end of said chamber, thecombination of a plurality of diffusing nozzles disposed in spacedrelation about the walls of said chamber on opposite sides of thecentral portion of the latter and adapted to discharge into theperipheral zone only of said chamber an aeroiorm quenching fluid freefrom liquid components, means for supplying a quenching fluid component,under pressure, to

and said nozzles cooperating to surround the supported annealed articlessubstantially on all sides with a slowly moving, homogeneous and.

uniform, quenching atmosphere consisting said aeroiorm quenching fluid.

0'11'0 OECKL.

